SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e5784e6e3263f0eb079af8185d13fc45891cd621921eda5f008440233998a2' 
  AND token = 'hU80vCrorSoypZIic6GI8k5eu6nIDcXdpqxQGkTZBPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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