SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f548cf3e3153c9409c35035414d9cbd7969ad6782de88319903976e973a496' 
  AND token = 'C4eKTjaf1ewD6GMXuADz9EUK1T7D+1O/XI1nQ9kPM1o=' 
  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"
    }
  }
}