SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd9c85965695123177d724e691dfd82f876cdb8952285270092b9d11f6ea336a' 
  AND token = 'X5m0OwsB8GSZ7wAvIgRDgJQUIFsOcBEL2zBfxV0sZxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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