SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27255a35035380bc9c2a6cfce23495a8b6469da6d3b4a095951362fc2bc5dd79' 
  AND token = 'TeGzZ5GvUy9h7dUEPv/M2sqzJI7Ec1cQBZghW6wQFlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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