SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bef0231576b4129949dad0c84a906ee6878fabe897ecade86857bb1ab89819d' 
  AND token = '45gzuxj3Mv0jgbqoU6j7CAbhQIRi1Tde/qcxC5LC2Yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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