SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb6bf79ad422527ce00c93e1b5aec3992bfc1438a417ebad78ec6bda47f3c436' 
  AND token = '4ZV36p/3H57q0psnlZZsZMpZTgOiqijBO1y6e8Ns2Fk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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