SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cecff58f8d5bb2568d76d15d8f6738fc80375f30831484a5382ac3745f78e40' 
  AND token = 'je0StRBcGUdkLfP3THz3eypIE/btbutDYXvQFSNy7mY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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