SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58e750122460e919fc74355062f5919d5d9b958ffdb8bedc08aedbc9d53425df' 
  AND token = '1KsaIh6tbgXZAZkpJVleOrbaS0ksrpujshfup7ntisU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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