SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f634b36186b1ab382f304fd47c8e71b77349bbfb54c861c724badd61a5b2c47b' 
  AND token = 'EQBmPYB+P34hUoYS1SsGVt2MmMrgkvSi0sD26LejTRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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