SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91030168a4f7255d0af3903db03dbd2b04dff5134cc2233db9d37570ee0c9794' 
  AND token = 'DfI37PX6DP5cXgbQ9slrOUJWIJj4EObyU3OeVyJkfQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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