SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '797c7691c52b1f85a4fe36ee0e1f43aa04ab971ce79513dda487a7d699d8d85b' 
  AND token = '2/P8OkQyOUc4TmVixoxuM92RjGT+qeqZTavvbs4zJhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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