SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d0a04862a274dcb357dc8898d5c1276b58e59ecd69dbbe223c9989b156d66f6' 
  AND token = 'zlIt80cwnFpqIVjZFVwHipeHhugB/mhigwaF/eq+KO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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