SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a14e79d133dc2edb78b94d7b916bf228343ea7e6acf2fbb7ec5ee2ac7645cfb' 
  AND token = 'zWcD/ktka6omW68dQrzYSoWJxcPmD30rgatMCNKxrB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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