SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '736cea5e3a50ed5a96d8dd566236ab445e64e69eb32e78b28bda4a58f31f51f2' 
  AND token = 'mc2dSws6vRH1j/rFveQsbxMT7SkeXcEg7VQhOFF6G54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}