SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a36a4fa4846a8cafff3af445d157fa8b754f9b37bae23786782c8017fe96040' 
  AND token = 'wroKxykBv4LV1dGWlUGiIlWvmRXKu5EyUnP03gc9Ngc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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