SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff4beb88e1441b176164d7cdc514d22a87ad972a9c221686698d4f1971ec1fbd' 
  AND token = 'AEnSskQ94sVU9/m7cNfDc+GwJa3EM6n+z9BqmGlD5+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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