SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b83cc85ddbd3d54a18bf61120d5fd52708aa8a2f557e720135834c967c12a25' 
  AND token = 'zRYqF3bZEMYNkaoEB2X0XphYl7/1UEusy84b6OmxNdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}