SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02dfec8260a11bfe2844e920d70068c17508bce521927deec465684eeb1b9f0c' 
  AND token = 'BA1+txlL/JU52xxCT+Of2TCK5PH+iwGlUiyi+gpbLvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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