SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c565e2860f0fa8be35bd09e40cf1353790337edcceb9f05f8d19b2cb0916d6' 
  AND token = 'x+96ZmiTgjSrQQYmR7VaOCjJnBGczbYK2ffZZZ7orwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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