SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '550bd811ec3c3f37a87fc27cd2506fd4f014b392193687e85152847250a2ca0c' 
  AND token = 'xz6Io7Qmx/C4hIUfO0zistSMok0Cew8kk8OggOOWx2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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