SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c433667e0e380c65d49f32de9a94e8723029f81e56f5bcb8e1167ab841aef597' 
  AND token = 'Yj9UciSu9ttcVpNhIDXJLb4pFwB7an5eUv0gnrRq+CU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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