SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1d9a0dcc78537fed7b4945b907f59ef44afda89ac42420ce66e26384665b6dc' 
  AND token = 'Uy5CJx/YnK/qGZrdAvrWicJrTrgHAHR/QJoluNVDZw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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