SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f367c1f5701a297ecee7498e342cb7401b98688f5f13c7b9e4513749bbba31b' 
  AND token = 'pJ2sxAJdFBKJPqqDINAV8gRaJzErsOtT0hCNKHd/8PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}