SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75aa109b92a289450d9381ed9b0be0647d1be816156443fd5fba8dc4ccfb4b8a' 
  AND token = 'JmfRwcBH82wTZWiryWdNgTD631aFKXVDdNgTu48e1io=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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