SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7766ec37ea69ed02c84f3524f4b24c03ab4bf7cc712f965a38c9b30e4863450' 
  AND token = 'oFCXiIZOJWOxxWnfbypr539XoYqGOo63pXPW/DnGUQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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