SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5da6788d7204b3a2eebaac07f8c51a17e84af29c649381ea9fc8c991505f19a5' 
  AND token = 'm0OpqdMjYjkXLsIHVyW7VqxPLH8DslkzvQeav4Gnt+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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