SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67743a7be34077caa2434c755ff2b983ac4503d863fb032e15b693e4ae7f7d9d' 
  AND token = 'r1A5tk6IT1tAIPZwqT2alXm129HqZpydSOgy0RJTsgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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