SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46c4268267281d5c3aa645150d18f517a85b99301ae949597c8ff6d3fe958bc7' 
  AND token = 'eG0KvZtRy3O+MgmV5fNwyzTJDHM3Gu527RP4frfA+/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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