SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '39472cf44055f2b70aa9251be8b1dae29946028027ae7436d3afb7783b33b8c4' 
  AND token = 'SjHtCxvy4PKbgY2BotRNxoTlhX8zNI2r0IlP0h5wrmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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