SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30cd6fabc29ea5539f3f5bef88dea20557d6c92f33e5fdb6d31cffc6675aa64f' 
  AND token = '3FqH1dp5cHzsYCCsbXS/fi6TF6aTHIuc9aDCKVSLYx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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