SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63761db1c567832e4c24356e12539c2f784ff43e629edd7a69b8adecbbf934a8' 
  AND token = 'qBQUYU/ujCVgrPchD7MMKDrbYoKrilSxd6j7cQMe0Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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