SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab5e3baaec0bfc8f7d9d71dfd2fd81a264d2eaabf2eea3641854c8783679b175' 
  AND token = 'zZdzdcdMdgVtEh4uDfcmNGEpenUTrrg5BkHt27dpZUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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