SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf62eb2ff63fc7245516eadc3859436ab484b76d6dc8e23991c0e53fe56f6427' 
  AND token = 'qbE4hX4MIdiYs11jtv1Orui0KG/jgr1Nu7loJ+lx+Ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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