SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fe11c5adfe145ce965d9d622029fb8ae0bc872ee8c972b6f44ca5fb02ea8350' 
  AND token = 'gMYuMkeTAzQgQL9GtlzVT/3zuYfOIdOjO+wdLOkQXUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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