SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '739e465c0a4704581d29aea4813b07ba67255e15edc36d85453cc11ea7136782' 
  AND token = 'yEbwUerHza2droyscnoN+FCtdNYtBWdKuBtxkrCW/N4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00138

JSON explain

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