SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab390f285e36cdd792f9de971715eff67dfc0df9893c1b4b6504081a7f7229d7' 
  AND token = '4/iP7Y6H5Y8rxjF3+24/8OUQOorq8/yh/bVjCMElLrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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