SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '279a14e80c4ff23d15c88bc8886915991e805c8337d326c6480203e33cf6ffb9' 
  AND token = '1aXVXvtFydQ407v+pZCnnFElR/wsX63T1KtqDqjHJME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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