SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17fc95db7823b24821ae4bceb06fc99b4633ac53658a4cfd79b970e9cd1e28ce' 
  AND token = 'WpoZqlDLtzVYMQ4pGBeSDAtVyz24dKUpAkfReSHOEh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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