SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d509ffbdd6d8dfc124be24eacd017e90ad82bb369e5be60a618a5b14b4a0c2' 
  AND token = 'baQzqd0kqLdFvHcymMGYJNswLzC9Y0wxGgvsbDexMjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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