SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2b92ba925e2365aed628a49b7b414a63ce26457f6caab19f13cf306eafada2c' 
  AND token = 'RUO/2MLvoLePWv5mprzYA9tdIeYcHcsFxBTzMNoJTPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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