SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aff5c26f78487fd87f204c4f4e2d92a05783d72456993bd81b6fea4e42973075' 
  AND token = 'fWt7u3lFamTCKwqgOjz0dZ7vJljdhmlhgAmNwDhigXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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