SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19c62d5e994885720eb640137772e7eb3a2ce9b562d3c351ed8922707369964c' 
  AND token = 'vWkzCanNMaBoqT/4eeZUc8oqgxdQktmwjIAJjy9i/4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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