SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cecad1c5b16aa5cb3a7aa51158fcd9999e77fda30f140f3d5f3b319a5eb028c' 
  AND token = '9wJh2ogVZe8fqlOZDltbiaAOfAe56zNzk4+fhqJnwyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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