SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ccea59e2b065edd9f5ad0f917c0ece2255a105858abea509d37012b42fee9fb' 
  AND token = 'yD6wdVat0DBDm7Eg9rvWDnJzUZbHBQAtfSXd+fmSjHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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