SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b5b3f901f5100d8fbac1cfa79f1253c300c3421a6116460d98ee47445020d84' 
  AND token = 'ghLgQDzAMH1WJVQTjr/D5RFDZEPGq2sxVrzQFcodcRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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