SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c79cbb994f297c7e8dc903c6dc6c8849ecba83c3eae326a87510ce2555b0653b' 
  AND token = 'YjIvJI1OqLfCSJxf9R+o6Sxif/q4gCr5LZhvTlChM0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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