SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c80283a14685324b9d9bcf098c41fd0b7fd5a08e5e2bd2c21864fe022e44922' 
  AND token = 'krb53IQgIbDeKmpbcOcx8Gpt2opM7PrSy70pVYPcfkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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