SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e2320483d2b3bb883895e4b7b8235dce9f7dea71cb2d3d0fba13cec97160ca2' 
  AND token = '87Tx4+BqkOHlBGbMYdiSlnhpqukn7YHGHaGWoKXmMXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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