SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8097fcd395347b9c1e67f55b0a0228180f81c52f3eb66d6106e01a9394becc47' 
  AND token = '5OVKoO/V9CP9keLKobXTL0/x3dIhzvnT9afSqK5j/nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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