SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed8e8751cae71e85ed10c3c792e63ca4da440dc720cb9aad96e48e1d4f000fe9' 
  AND token = 'rJqYw830e/AOLkVNZnsFhncu/EcESgIscLjDeKUgfCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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