SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc437fac4e2bdd41529e90dddab3875a8fe4bec04d8a4575d00c2a9629ed4667' 
  AND token = 'VxhVfUmNSBuNPLLIigF9hGtlTjq0HFrWUHvW183GBXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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