SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f47d4c994daf21660c4aaae7d0c4a7d191e2ebc12b0f0079846e70bba202cba2' 
  AND token = 'kCUTuC00eIozglaBlLy7Azv3WPhj3spqXS0eezy/2Fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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