SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '141b721ec138ddadcdf5c3667adc8f1695e8d50b6e5e493443226ea23201f409' 
  AND token = 'K/9dusTEfX2Iff++1KiZKEp3DX+P0PJp8z/D95HZXQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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