SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aef26c488b7633f3e4d7e88bc348f13f8ad6592f500943e71f228ff5f048e3cf' 
  AND token = 'qrIoM76qa3F/YEUGNVMg5VYY7kW+27ShBS5h7KAXvZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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