SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37fd495718a28bb01ce466f01fac286d73ed545c9dfe5607d75779b73608446e' 
  AND token = 'ALO8jaRZ6SV6rR4f/fGw9JPzGGzLHnaJxpoaSH1Cq/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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