SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ced434dd51433b570852a160697118cfb776548431a8369350033b500dff6dc0' 
  AND token = 'M0q+h2KpD4T71VxWt0BjzwLRrHuFvTBGq+UHhrE7Gus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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