SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb2b9f12da27d030d69fa8dbba3dd3d4275bd0409bd789b990a07093cf753675' 
  AND token = 'pbu5EKYXJL6UEX++OYCEJBrsuir2xAxSI6OWAHIp25I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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