SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63b9279336059ab1b59efb4b29283f7c759d58c84e260bbd6029c8c6e44898cf' 
  AND token = 'P8z6R5bqClvyjcPNZrdfQmNv6jGeE+ewNYPjIPDdV3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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