SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '394a012ff6dc3ed470e907b775f61994308ee1a38dd305e099e3689f88138e35' 
  AND token = 'N9/jq9G4xzniSJm2FZRqsocv6xHt/izUStJ62apglnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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