SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fe8cce0d4890303229d48bacf250df2946619122e2cd67327bc5e59ce7cc20c' 
  AND token = 'zmbQ/LgSJQH5BHeuIWpzcPMvFGtILwmQehyX5/7ZZPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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