SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bfac704f61ca6d2b6d5bad41a5c86d735f040e03b5c29fb8c27bebddf0ba61b' 
  AND token = 'B72l5XDiZwILt1Rhk4h9HUwMUmIwHXhv63Ehosgwnps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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