SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40775bfabbabeb59f7c09d67661c45a962e2f5acb4e5208985f5b92b10f742da' 
  AND token = 'amuA+7x6BPCpjDhhXwMg//ibPLTYLV+tgPSbSPb/o/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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