SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65e3cac357a1bc987485280dbe07a2406d0446939233b726ddc19d86ffba4fe6' 
  AND token = 'R4uJEMXBfQLhG9M6cbHxeOFGP6aSS03nh5TZHvWjVlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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