SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49981c7ec8c37a7290394fcabef553e48407e3483dd58ffbea0c46973a15e80e' 
  AND token = 'onQCpcV0ttfVCUDUI75Xjbp/bLt66LiS14rDq7MJVIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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