SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffc87359dfe11d05540039b3b2b7deb675f01b195bb0a152158d09deebab621d' 
  AND token = '6q96bOItTMkR/vQJZEr6zPm0fiUTHY00Xw9axwbEDnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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