SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435af572542e4aeec14349e89b8d62a0bdeda86bd6eb2d47f249b8db17f34982' 
  AND token = 'xOqxiACOmvnVmQjB2SZkX6zmzJHjs1Fm6cbuniJB1hI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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