SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3742a59c599d8ea373414a71ad57c70dbd1653aeafd5fd667fbb46dc96669c32' 
  AND token = '/zaAZ/t7ui7bYBNhWZgfMCEAcCqrqyramR4IBLhjItA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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