SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb4b9c6e93bf8da38f223402e8332dc49093605171f4f2b416fc58b95c5531e' 
  AND token = 'eVZUZoyDsHKT0M9e1ZVev2rBxHRqRSsnegANQXHIpr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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