SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7d4df1fc935ed84a4bf54c1e8cc4aa6de4c3ca58dcd21b86bcab93c8223d8e5' 
  AND token = 'RkPhRjY5LacANAlOjGXqFZ2wUdCywUZDQEtuAN7h76w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}