SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '212694aee867cd31058f331a61b26b98b5cc26dd4cc151a955da4eb02125121c' 
  AND token = 'iHZaFTC8jNgKI6550snBPKpg5Vxc0YKz3vkMvLAZQYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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