Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15f7e6233e91345a874555e0077fb3922dad04af094a1820489874751810b58a' 
  AND token = 'im+3g0hO+AfOI+e2ncSACuBb9shlBcTO4SWB46E26AE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}