SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c74586346a0d1a54fbba4484ba826372579bd9c75fa14fffba05608a59ef09d7' 
  AND token = 'QlVhpcYu2rf/rT6UMc6CYGpww89QQSMNr8EISTmvL5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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