SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6328b8f7047ad5c8310e4fcad084536e849be24ba3c9a26a8c84d16a8913425c' 
  AND token = 'X1ZnjlgZbrwY07kTCIr22pn7mLJXcc/H5dBq0Nllk8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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