SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3e0e36a7b2dded5e2effd9a20e678b7418606253023a6a150d5fd328a0de587' 
  AND token = '464qIFMZ0m9jKoRNg9qZKKqvevl+Gvd0DpnqfBB5beg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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