SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f48897013f0f99cb64d2da7e499fea35edf26c5c514b3fd291e4c247d6cc07e' 
  AND token = 'uP5DFKp2JSBRDYqOE6zVvobd+wuyZgaEec9bsITwauA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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