SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aad9ffb173b666e489a9f0e0531b424759be3630c141c9eec3646364890f416a' 
  AND token = 'UUFkBj0ki5z6ymh/xlqajrkKRY314awj3tjxd0Ti0qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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