SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ab9f1be37edb25308369731f8d0d4c556b90ce01a00eb6592706b8b8f5864c1' 
  AND token = 'NXaIWtiaAA892Cnd1p0ybLuDzFobxuYXtpux3YznggE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}