SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6460d8513e8394c93ad02bab8d4e37245803827f59a0910eaccd784b8f4f4b20' 
  AND token = 'uUEFmaz7g7Kqm5DVQ64fj2XzMBGyyZN1KT7mv+GpKUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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