SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96956a1727a9ca94e192faf2eb9815ab4691af77fb82c39ecf522ea7b9ed43b' 
  AND token = 'a4iWVEKc93ocvgcaJQXDes4zsr2xpOPUHa7VZBHhVlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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