SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83624c944fc859e52b92dc47fb5c82779c14a2dfbc859dc7e85e06c516e074b2' 
  AND token = 'w1VtCHlDXRP9vXWLrqtphEzmvrnE9ujCwiBUnaMx3Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}