SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '064651b0f9d70f1797fee05ef6fa9b128e60f5eaaa08293683fae0da5aa63c7f' 
  AND token = 'GNQ1eAYKwPCprwH2mCrOXQczYdeuy9IdlYQPRmAr5J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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