SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ce0a3b0111734a405f5bae73b3e0b7318f999df2bb206ffa98a14afd250fdda4' 
  AND token = 'C4mgJIEuIwMWsrFhEoZPkyhqiOKHZQyqazE8kxwVY4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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