SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fde190c7ef6f8a1082dcbf1f0cbe4e957d208783cbdcb3dd53a85beb9a9639f9' 
  AND token = 'uViwEJcUS+qSMXrf2n/sJDIRDOYj5TX4CbN+Bykj8Uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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