SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '112da51942cc0bf07da0e7b47411fd4c092eed875e64f5dd79fe34eaa7841bce' 
  AND token = '+muCBvQAfaWQNgRf6GYxUBh+OBdXKPuir3PCUkxO+X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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