SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '73819c6cc6d136813a63d465c45db37c605f431d56cba725f6b4c965e05547b2' 
  AND token = 'dUjGkJy/4/iwX5KlJklpVB6LQ73xthacBMYGoaSfnnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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