SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0c970e8b870c7a7c163ad4cbbdc5469d0500ee382359a55fc8b753a5a3d8c692' 
  AND token = '4mesOUhO4XipjTAUBJCKTVhgTvPVmFQsEmCNJclRXK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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