SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b4910003cd448d0e8a64ab9821dec94e4bebf0f554260169fc9751f82cea03e' 
  AND token = 'BVEQCbv0ltjPBsegBYLJIfJpQcmAsUvJJjucDORkNVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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