Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9b44168aa2e0e0ce4813e5913b4683b11e81c9552d1fce0d79219f01f05ba76' 
  AND token = 'NKm5IIQ1ftosr3FsQYLwTaR3w1fg/QZ6Bm7d95RxKvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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