SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '483dcb026fcfd7aacb77e90d7fc116f0053ffd7fc02b57c1dbd58ae9860188cf' 
  AND token = '5bJgPNyLd+8iw5+4GvcqOAqBsImmHcZ87Mmpm4T0IJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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