SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b1b6c0fd983aa29f36501cce69162829c44c1d5b01270d379b2224781cf9197' 
  AND token = 'yYjQCx/2BsQrqOtiqxlgb7sVLRGnGhz4sFAqja7NQ7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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