SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61ffa927b1a56c7f92c5c212b1b896b2ba6d53dfca77083c1c72dd2648316913' 
  AND token = 'EIBJxj8l+5DhqhTEpnLrPmYFLrKj7yixxATYgktrJHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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