SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39390cd78d79dac33b293bcdba9728ae4aab08004ea9d05392b193ec5184f182' 
  AND token = 'Pn5OF5b7XgcLbggenkBAMe5wjGPyqpiLbYb1v2ydVYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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