SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '729ee2334d96346351cf653462638270c4898d595d9968b808d47f63da814af4' 
  AND token = 'O1kUwWzH4MW0QVGDPHaM3EymXgAqfvRFok1mZz6Mx/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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