SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f597341a6dc25adb0003db5fc17c8210c6a52f79c0633f9677dcaf6b79858e2' 
  AND token = 'B+Hn0Iqe6S9NcIdSHnZVmoDmm32d4xMLpC/twoFHPj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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