SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feda82098c6457dcb3472e45b92c4c949b07f152bf580a17464f004e28aad7e5' 
  AND token = 'uINy7CyUwCEq5xm1GcYhn5P1XdgdtlBo2AFCEauWRnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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