SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c6c4ad40155cb57e9b261750e8927f22b1178304e5c058fa405477bb6dac37' 
  AND token = 'A9ONREdmRyzEN+6ipCzuV4F92yVmabd0oTh4UjSHUfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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