SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b45368e448178598f4b7bd76247d213068806509773271ea930036c9b5e192c' 
  AND token = 't7lH4wsH1VZN9jus0nACn5CdCvhuTkbXOjQql8ork2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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