SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5418277290459cc83319fbf10567542e57c9c12133fc302131d1dd33af532efc' 
  AND token = 'WoHBTdkgi+Ga5cOv3vVwNDO5pu2FIlzyxBm5eUs0Z7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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