SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbf519b24ec5dbabd903b8d4192ffdc47ddefced044ab0aad02ef66d2a9eba4b' 
  AND token = 'I7Mj8svpxIo6CJDS4eEVj3M4HMGVNJST81hBuqYVj1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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