SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f448bfc7c8694bf0620a4d542e0fe4d3bb6b9ff68f9572a55a3b5830276068d' 
  AND token = 'pJNxzwBQuDqt+wCUOTNR9Psh4krwxqvk+/vD0jZJH+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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