SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09853db54a5afdb11d2ab3063b06bb5c828be30441963f83ea3d0350b0c55fa4' 
  AND token = 'ZK1+UBzYLEcALfq2zt/BB8aZxwR5xNTD+VpK9S6rBhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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