SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77357ebaa2ea7223fe226d7ff165c98b9415adb9a19758655c107fdce4032830' 
  AND token = 'Mm/UStfRLDYaJcpEl50y1JQ2HhUWEh6kokvNnFnPMBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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