SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c4570884a832d851f403100b791e6cbfbf5a9d602a69be3605fdd3488b1747d' 
  AND token = 'Z0RJyD4iSRxwfT/FDEivO43NHkpr5bQngmGXwTs7IfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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