SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a5bf05721fa30fa0d8ccaa3d4898503ca428ea4953857827fbba88f225faccc2' 
  AND token = 'Bufaxb8SOZGJD3hFZq1zRJyiPvHgLaLeSPTpmW3YNWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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