SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e09863f6766955035a208088ea12b75489959bce9cf3276488e49b9c205e316' 
  AND token = 'YNmK0sMqTSmAjU5QzbcxwJTpVwS6pRSj5T4mX31DaLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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