SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '342eb4837434b915d0320f02f85c84cb5f58cd9c8119a152011379d2bf30cee9' 
  AND token = 'B7/hN6MkjaMZLgFJ51M5B2YWT/KbWA4ApnSVC+63w24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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