SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf09ecfeb5248042bd144796e048f5c976bd0a387b554fb4512c2cf45fc4b950' 
  AND token = 'V+an8PPrGQgswF+yrB701zIJPXoDOgkZ35HSWCLmt9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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