SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '00ca8f3213b7968d3c8062f52f847c98f3d2ba45d26e4b654296b69572f4c970' 
  AND token = 'ETVmg1vFOGKEo6exPLIivZYo2WQJ7goL9xG17bToKc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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