SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb9510714147b93396f61f593031acc4e240bb9ad84a9e627bd2e412acf40820' 
  AND token = 'UD4f5ROLnE+3FKjC9W+kpiCcfQs44k2ae3d1JcPdNU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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