SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c9c213f65a88f63ec4640d5cc423f6156109571448d66f69dccf88aca3ba42' 
  AND token = 'o+1dXIt/P4PJZ+vqRz7X4b9lgoD9i18FSMvTIYjqyJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}