SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8aa9b2f2a99104f98ed8e0dfa7311aba3ee4b22b579c7636bcc661661348df1' 
  AND token = 'NYgz9OknczYLHXcDCVFkeflEmpDVfniyroE2JjEN3+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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