SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ed5b6bf59c9b7782ee50899543c0d9b4293777c083304c3baed7973120e6504' 
  AND token = 'RFAmYxT0ZckJdBwzV8CMO//5RCXQhmeUuu9HFj15jkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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