SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e6bbfd7331085e29aaaca6846685b665be8947a5c9b53717480cd30b4e6a10' 
  AND token = 'ud6jbNEkzTTuXCvlPdY/SE95xqy36KhjICN4dtLfxRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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