SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a36583befc7e3cecc7ffdc4110c09398399844c3d906f62510de77174b641a9' 
  AND token = 'TrdXyC5jONL5hy2qWnDOfeeSpxIcSCDigw/4vUKZnRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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