SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e663660aba56863e801354419ea2b30c4c214274920f2ba220bdecbda1852de5' 
  AND token = 'QQniKpaJ0+GghfbJ8LjF5iTcB9TMO+CA3+IKMHqWms4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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